Orthodontic arch wires are commonly used in the field of orthodontics to apply corrective forces to misaligned teeth. The arch wires generally comprise a single wire formed into an arch shape corresponding to a patient's dental arch. When in use, the wire may be secured to the patient's teeth using a variety of devices, including brackets bonded to the teeth.
It is known that different teeth in the dental arch require application of different orthodontic forces for optimal root movement. For example, anterior teeth, canine to canine, require lighter forces than bicuspids and molars. Accordingly, arch wires have been segmented into separate sections corresponding to different teeth in the dental arch with each section of the arch wire capable of exerting distinctly different forces. For example, one section of the wire may correspond to the front or anterior teeth of a patient, a second section may correspond to the patient's bicuspids and a third section may correspond to the patient's molars. Each section is then provided with a distinctly different modulus of elasticity, which enables the wire to exert different forces on the different teeth in the dental arch.
However, because of age variations and other differences, dental arches and teeth size differ from patient to patient. General use of standard arch wires having a uniform segmentation of forces may be undesirable as it may result in orthodontic forces intended for shifting one set of teeth being unintentionally applied to another. For example, orthodontic forces intended for shifting bicuspids may be applied to the patient's molars. In addition, application of incorrect or unintended forces may result from slippage or movement of the arch wire after it has been placed in the patient's mouth.
Consequently, with prior art arch wires having a segmentation of forces, it may be necessary to have many different orthodontic arch wires to conform to the particular dental arches of individual patients.
An object of this invention is to provide generally standard orthodontic arch wires capable of exerting varying forces on teeth for obtaining proper root movement.